Today, sensor-bearing units are commonly used in automotive, aeronautics and other technical fields. These units provide high quality signals and transmissions, while allowing integration in simpler and more compact apparatus.
Such a sensor-bearing unit generally comprises a bearing, an impulse ring and detection means facing impulse ring. This impulse ring may comprise a target holder and a target including alternating north and south poles, whose number depends on bearing size and particular application. With a bearing having suitable dimensions, impulse ring may be fixed to a rotating ring of this bearing, while detection means may be fixed to a non-rotating ring of this bearing.
With a bearing having small dimensions, it may be necessary to position the detection means beside the bearing, while impulse ring is fixed to inner ring and extends radially beyond outer ring of the bearing. Together, bearing and impulse ring forms a bearing device which can be fixed to a rotating shaft. However, when shaft, inner ring and impulse ring are rotating at high speed, a deformation of target holder may lead to interferences with outer ring, what must be avoided.
FR-A-2 884 367 describes such a sensor-bearing unit. The target holder has a specific shape and reinforcement ribs in order to avoid interferences with outer ring, but this increases the manufacturing complexity and cost of the impulse ring.